CN101019338B - Suppressing echo cancelling in packet switched network - Google Patents
Suppressing echo cancelling in packet switched network Download PDFInfo
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- CN101019338B CN101019338B CN200580030890XA CN200580030890A CN101019338B CN 101019338 B CN101019338 B CN 101019338B CN 200580030890X A CN200580030890X A CN 200580030890XA CN 200580030890 A CN200580030890 A CN 200580030890A CN 101019338 B CN101019338 B CN 101019338B
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B3/00—Line transmission systems
- H04B3/02—Details
- H04B3/20—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
- H04B3/23—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other using a replica of transmitted signal in the time domain, e.g. echo cancellers
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Abstract
A method, or corresponding apparatus, assumes a call is a Voice Band Data (VBD) call. The method disables a local echo canceller and transmits a tone that disables distal echo canceller(s) along a communications path across which the call is communicated. After disabling the echo cancellers, the echo cancellers are allowed to operate in a typical manner, such as according to ITU standards, after the call is established, including remaining disabled if the call is a Voice Band Data call and being automatically enabled if the call is or becomes a voice call. The method or apparatus is particularly useful in networks having Point of Service (POS) devices that have modems that do not send out a 2100 Hz tone to disable echo cancelling in the communications path. In one embodiment, the method or corresponding apparatus is deployed in a gateway.
Description
Related application
The application is the U. S. application No.10/958 that submitted on October 5th, 2004,751 continuation application.More than whole instructions of application are incorporated into this by reference.
Technical field
The present invention relates to be used for to suppress the method and apparatus that the echo of packet switching network is eliminated.
Background technology
Because the low falsetto effect (pseudoacoustic effect) that postpones echo in the environment, conventional analogue and Time Division Multiplexing telephone network bring the echo problem of can minimally feeling for " the virtual direct connection " between the end points.Dispose voice service along with the telephone service supplier utilizes Internet Protocol (IP) network and other packet switching network, especially the voice user can find that some callings are unacceptable, because extra packetization delay makes echo be felt more easily.Doing a lot of work aspect the voice quality of echo elimination and raising audio digital signals.In fact, present most of gateway (GW) product comprises that all the echo elimination is as network characterization.Provide the IP network of voice service to be called as IP-based voice (VoIP) network.Nearly all voip network also provides the data, services that is called as voice-band data (VBD) service.During VBD called out connection, any Echo Canceller in the communication path all can reduce the quality of VBD service, because Echo Canceller can change data-signal and can produce beyond thought mistake.
According to International Telecommunication Union's standard, if any telecommunications switch detects the tone (tone) of 2100Hz, it will forbid its Echo Canceller.Here it is most of modulator-demodulator any training be connected before send the reason of the answer tone (ABT) of 2100Hz.But, still have many modulator-demodulators not send the 2100Hz tone and come the Echo Canceller in the disable communications path.These modulator-demodulators extensively are used in service point (POS) equipment (for example card holder's end) that uses low rate modulation modem, and v.32 said low rate modulation modem is used and the more modulation of low rate, for example v.22, v.22bis wait.POS equipment also is called as point of sale device sometimes.
Therefore, if Echo Canceller is activated during VBD calls out, it is insecure then connecting.If during the audio call in communication path (for example voice gateways) Echo Canceller disabled, then it can make normal audio call echo problem occur.In addition, if in the outside communication path of local gateway, have Echo Canceller, then just have no idea to utilize local gateway to call out disable external echo cancellers for VBD.
Summary of the invention
Now also do not solve known solution with reference to the problem of description of the Prior Art.Voip gateway allows its Echo Canceller of user's manual deactivation, and if have the 2100Hz tone that offers Echo Canceller via communication path, then Echo Canceller is disabled.But, the present voip gateway disable external echo cancellers of also having no idea.
Therefore, principle of the present invention comprises a kind of method and corresponding apparatus of forbidding any external echo canceller for voice-band data (VBD) service that on voip gateway, realizes.
According to a kind of method or corresponding apparatus that suppresses the echo elimination in the packet exchange communication network of one embodiment comprises of principle of the present invention.This method comprises the local Echo Canceller in the disable local network node, and the calling of said local network node and the support of far-end network node is established via said packet exchange communication network through said local network node.After the connection of calling out was established, this method was sent the tone of the distal echo canceller in the forbidding far-end network node.This method also allow Echo Canceller after calling is established with typical mode (for example according to the ITU standard) work, comprise if to call out be that VBD calls out then keeps disabled, be that audio call perhaps becomes audio call then launches automatically if call out.
In one embodiment, tone is the 2100Hz tone of anti-phase.This tone also has adjustable length, for example 500msec, 100msec, 1000msec or intervenient any length.Depend on the network specification, longer or shorter length also can be accepted.This method can also allow and selectively enable or forbid sending tone.
In one embodiment, forbidding local Echo Canceller occurs in before the transmission tone; In alternate embodiment, forbid local Echo Canceller and occur in after the transmission tone.In another embodiment, forbidding local Echo Canceller can take place with the transmission tone simultaneously.Sending tone can realize through sending the data of representing tone (for example hereof data).
This method can combine not send the communication path that service point (POS) equipment that the 2100Hz tone eliminates with the echo of forbidding in the communication path is associated and use with having.In a kind of network implementation, at least one in the network node is gateway (GW).
Description of drawings
According to the description more specifically of facing the preferred embodiment of the present invention down; With clear aforementioned purpose, feature and advantage with other of the present invention; Shown in said preferred embodiment such as the accompanying drawing, wherein in all different views, similar label is represented identical parts.Accompanying drawing is not necessarily drawn in proportion, and emphasis is an explanation principle of the present invention.
Fig. 1 is that wherein gateway (GW) has utilized the network diagram of principle of the present invention;
Fig. 2 is the block diagram of gateway that has wherein utilized Fig. 1 of the principle of the invention; And
Fig. 3 is the flow chart of the process carried out of the gateway of Fig. 1 and Fig. 2.
Embodiment
Be description below to the preferred embodiments of the present invention.
According to International Telecommunication Union's standard, if the tone of 2100Hz is arrived in any telecommunications switch or Equipment Inspection, it will forbid its Echo Canceller.When on both direction, detecting the mourning in silence of 250ms, switch or equipment just automatically reactivate its Echo Canceller.This method extensively is used in the network that only transmits data, for example modulator-demodulator and facsimile call networks.In case terminal modem or facsimile machine receive calling, the answer tone (ABT) that it will send 2100Hz is forbidden any Echo Canceller of making a start between modulator-demodulator or facsimile machine and the itself.
The similar method of principle utilization of the present invention, but on the environment based on the voice (VoIP) of Internet Protocol, utilize, to contain the situation that some answering equipments (for example modem/fax machine) do not send 2100Hz ABT.In case telephone number is dialed and before calling out by connection, voice gateways or other network node just send short 2100Hz tone to the called party.This has guaranteed that all echoes elimination between gateway or other network node and called party all is under an embargo.
The 2100Hz tone preferably short and have enough low power and come disable external echo cancellers, and do not allow the called party to experience tedious tone.Process can realize in the Echo Canceller of gateway or the processor that is associated in accordance with the principles of the present invention, and can be according to configurable.For example, this configuration can comprise tone length, tone power and launch/forbid.
In one embodiment, gateway or network node can be to himself being configured so that all-calls is handled as data call (as a kind of hypothesis), and send the 2100Hz tone to forbid the Echo Canceller in other gateway.In this manner, gateway can be forbidden its Echo Canceller, and in case detects and mourn in silence just with its connection.Following step has been described the instantiation procedure that is used to realize principle of the present invention:
1. launch the characteristic in communication line or the channel; Preferably very likely handle under the situation from the calling of service point (POS) equipment that uses low rate modulation modem at this circuit or channel, said low-rate modulated for example is v.32, v.22, v.22bis wait.
2. when calling out beginning, gateway or network node turn-off its Echo Canceller.
3. after number was dialed, gateway sent short 2100Hz tone, the Echo Canceller in its disable communications path.
4. if what communication path transmitted is that voice-band data (VBD) is called out, then it does not have to set up under the situation of Echo Canceller in the path and calls out to guarantee reliable connection.Echo Canceller keeps turn-offing during VBD calls out, because two-way mourning in silence in the path, do not occur.If calling out is audio call, then gateway detects two-way and/or voice, and launches its Echo Canceller.External echo canceller is activated according to identical mode.
Generally speaking, voice gateways are sent the 2100Hz tone to the network node (for example gateway) that is associated with PSTN (PSTN), make and call out once being established disable external echo cancellers.
A kind of in accordance with the principles of the present invention process or corresponding method realize easily and have the following advantages:
1. do not need detection algorithm to detect external echo canceller.Detecting the algorithm of external echo canceller may be very complicated and possibly cause wrong detection.Under the situation of wrong detection, external echo canceller can be disabled, thereby for audio call, reduced the voice quality in the communication line.
This process realize easily, the reliable and memory that needs to use seldom.
3. this process is transparent for the external equipment that also has Echo Canceller, because all telecommunication apparatus with Echo Canceller all are designed to forbid its Echo Canceller to meet the ITU standard.This process has been utilized the advantage of this standard and need do not changed equipment or the process in the speech network.
Refer now to Fig. 1, communication network 100 comprises the communication network device of example.These equipment comprise phone 105, modulator-demodulator 106 and facsimile machine 107.The network equipment 105,106 and 107 can be connected to PSTN (PSTN) 110 or switch 115.Switch 115 comprises 2 lines to 4 line transducer (CVTR) mixing arrangements, and well-known said mixing arrangement can cause the echo 140 of the signal that between communication equipment 105,106 and 107, transmits.Modulator-demodulator 106 can be service point (POS) equipment card holder end or any low rate modulation modem.As stated, POS equipment does not fitted to be the Echo Canceller in the disable communications path.
Continuation is with reference to figure 1, and PSTN 110 communicates with gateway (GW) 120.Gateway 120 is connected to Internet Protocol (IP) network 125.Similarly, switch 115 also is connected to IP network 125.
The local gateway 130a that comprises Echo Canceller 132a is connected to IP network 125, and also is connected to switch 115 and gateway 120.This gateway 120 is connected to another IP network 135, and the far-end GW 130b with Echo Canceller 132 is connected to IP network 135.Far-end GW 130b is connected to the switch 115 with transducer 118, and said transducer 118 is connected to some end user's communication equipments 105,106 and 107.Local with remote gateways 130a, 130b can be identical or different with other gateway 120, but provided different labels here so that discussion.Other gateway 120 also can comprise Echo Canceller 132a, 132b, but they are dispensable for describing principle of the present invention.
Communication path between local gateway 130a and the remote gateways 130b is " long distance " communication path, this means that the echo of on this communication path, propagating becomes obviously, has reached the degree that makes the voice signal distortion.In order to remove echo 140, one or two among gateway 130a or the 130b are launched their Echo Canceller 132a, 132b.But under the situation of VBD transmission, Echo Canceller may make the VBD distorted signals, thereby causes error in data or possibility interrupt communication service.
As stated, for example all callings of the network node of local gateway 130a hypothesis all are that VBD calls out, and send tone, for example the 2100Hz tone of anti-phase via communication path to remote gateways 130b.As response, distal echo canceller 132b is disabled.Before or after sending tone, its Echo Canceller of local gateway 130a forbidding 132a.In this manner, the Echo Canceller 132a, the 132b that experience in the long haul communication path of remarkable echo 140 do not carry out echo elimination, thereby allow the VBD transmission freely to carry out.Similarly, local gateway 130a can send identical tone 145 to other gateway 120 and forbid their Echo Canceller.Be to be understood that tone 145 can be the 2100Hz tone or be other frequency of forbidding Echo Canceller definition at present or in the future.
After forbidding Echo Canceller 132a, 132b; Local gateway 130a or utilize the relevant network node of said method to allow Echo Canceller 132a, 132b to work with typical mode; For example according to the ITU standard; Comprise if to call out be that voice band is called out then kept disabled, be audio call or become audio call then launch automatically if call out.
Fig. 2 is the block diagram of local gateway 130a.Local gateway 130a comprises IP network interface 205, processor 210, local Echo Canceller 132a and other interface 215.IP network interface 205 is communicated by letter with remote gateways 130b, and other interface 215 is communicated by letter with the IP network 125 of Fig. 1.
In operation, the processor 210 among the embodiment of Fig. 2 can be controlled (promptly launch or forbid) local Echo Canceller 132a and send the 2100Hz tone perhaps sends the expression tone with file or other mode data via IP network interface 205 to remote gateways 130b.Processor 210 can also be carried out and relevant or distinct other processing procedure of described method here.
In alternate embodiment, processor 210 can be integrated among the local Echo Canceller 132a or other circuit among the local gateway 130a.Processor 210 also can be arranged in another outside network node of local gateway 130a and support described technology here.
Be to be understood that processor 210 can be general processor, digital signal processor, customized processor or with the processor of other form of hardware, firmware or executive software realization.When executive software, processor loads the processor instruction from computer-readable medium, and with typical mode execution of program instructions.Computer-readable medium can be the computer-readable medium of random access storage device (RAM), read-only memory (ROM), CD or disk, removable memory or other type.It should also be understood that program command can be positioned at the outside of processor, can utilize various communication network technologies in this case via the downloaded or the instruction that uploads.
Fig. 3 is the flow chart of the process 300 that can be carried out by the processor among the local gateway 130a of Fig. 1 and Fig. 2.Process 300 begins (step 305) and judges whether it receives the request (step 310) of calling out of setting up.If do not receive request, then process 300 continues to wait for till the request of receiving.If receive the request of set up calling out, then subprocess 312 is proceeded and carried out to process 300, according to principle of the present invention, subprocess 312 based on calling be VBD call out or audio call come suitably to launch with the disable communications path in Echo Canceller.
After subprocess 312 was accomplished, process 300 was judged the signal (step 335) that whether receives terminated call.In case receive this signal, process 300 is with regard to terminated call (step 340) and turn back to the state (step 310) that wait receives the request of setting up calling.
Be to be understood that process 300 can realize with various programming languages when realizing with software.It should also be understood that process 300 can be reorganized according to diverse network communication factors known or that recognize in implementation procedure.
The adjustable length of the tone that is sent out.Example lengths comprises 500msec, 100msec, 1000msec or intervenient length.According to network that is associated with network service and applied code, also can use below the 100msec or the above length of 1000msec.According to the realization factor, the length of tone can be increased or decreased to and exceed above-mentioned scope.
Though illustrate and described the present invention particularly with reference to the preferred embodiments of the present invention, those skilled in the art are to be understood that the various changes that under the situation that does not break away from the scope of the present invention that is limited appended claims, can carry out on form and the details.
Claims (18)
1. method that the echo of suppressing in the packet exchange communication network is eliminated, said method comprises:
Exist to set up that voice-band data is called out or the situation of the request of audio call under; Local Echo Canceller in the disable local network node, the calling of said local network node and the support of far-end network node is established via said packet exchange communication network through said local network node; And
After the connection of said voice-band data calling or audio call is established, send the tone of the distal echo canceller in the said far-end network node of forbidding via said local network node.
2. method according to claim 1; Also comprise and allow said local Echo Canceller and said distal echo canceller to call out or audio call is worked with typical mode after being established at said voice-band data; Comprise if the calling of being set up is a voice-band data calls out then keep disabled, if the calling of being set up is audio call or becomes audio call then launch automatically.
3. method according to claim 1, wherein said tone are the 2100Hz tones of anti-phase.
4. method according to claim 1, the length of wherein said tone is adjustable between 100msec and 1000msec.
5. method according to claim 1 also comprises enabling or forbidding sending said tone.
6. method according to claim 1, wherein forbid said local Echo Canceller occur in send before the said tone or with send said tone and take place simultaneously or occur in after it.
7. method according to claim 1 is wherein sent said tone and is comprised the data of sending the said tone of expression.
8. method according to claim 1 is used in conjunction with a communication path, this communication path with do not fitted to be service point (POS) equipment of forbidding the echo elimination and be associated.
9. method according to claim 1, at least one in wherein said local network node and the said far-end network node is gateway.
10. equipment that the echo that is used for suppressing packet exchange communication network is eliminated, said equipment comprises:
Local Echo Canceller in the local network node, the calling of said local network node and the support of far-end network node is established through said local network node;
Local network interface, it is suitable for via the far-end network interface communication in said packet exchange communication network and the said far-end network node, and said far-end network node comprises distal echo canceller; And
Processor in the said local network node, that communicate by letter with local network interface with said local Echo Canceller, said processor:
Exist to set up that voice-band data is called out or the situation of the request of audio call under, forbid said local Echo Canceller; And
After the connection of said voice-band data calling or audio call is established, send the tone of the said distal echo canceller of forbidding via said local network interface.
11. equipment according to claim 10; Wherein said processor also allows said local Echo Canceller and said distal echo canceller to call out or audio call is worked with typical mode after being established at said voice-band data; Comprise if the calling of being set up is a voice-band data calls out then keep disabled, if the calling of being set up is audio call or becomes audio call then be activated automatically.
12. equipment according to claim 10, wherein said tone are the 2100Hz tones of anti-phase.
13. equipment according to claim 10, the length of wherein said tone is adjustable between 100msec and 1000msec.
14. equipment according to claim 10, wherein said processor also enable or forbid sending said tone.
15. equipment according to claim 10, wherein said processor are before sending said tone or with the said tone while of transmission or after it, forbid said local Echo Canceller.
16. equipment according to claim 10, wherein said processor sends said tone with the form of the data of representing said tone.
17. equipment according to claim 10 uses in conjunction with a communication path, this communication path with do not fitted to be service point (POS) equipment of forbidding the echo elimination and be associated.
18. equipment according to claim 10, at least one in wherein said local network node and the said far-end network node is gateway.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US10/958,751 | 2004-10-05 | ||
| US10/958,751 US7583621B2 (en) | 2004-10-05 | 2004-10-05 | Method and apparatus for suppressing echo cancelling in a packet switched network |
| PCT/US2005/034174 WO2006041650A1 (en) | 2004-10-05 | 2005-09-22 | Suppressing echo cancelling in packet switched network |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101019338A CN101019338A (en) | 2007-08-15 |
| CN101019338B true CN101019338B (en) | 2012-11-07 |
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| CN200580030890XA Expired - Fee Related CN101019338B (en) | 2004-10-05 | 2005-09-22 | Suppressing echo cancelling in packet switched network |
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| EP (1) | EP1797648B1 (en) |
| CN (1) | CN101019338B (en) |
| AT (1) | ATE499754T1 (en) |
| DE (1) | DE602005026542D1 (en) |
| WO (1) | WO2006041650A1 (en) |
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| CN101917214A (en) * | 2010-07-09 | 2010-12-15 | 中兴通讯股份有限公司 | Method and device for controlling echo suppression in network |
| RU2011107922A (en) * | 2011-03-01 | 2012-09-10 | ЭлЭсАй Корпорейшн (US) | HIGH POWER SIGNAL ATTENUATION |
| US8733641B1 (en) | 2011-06-14 | 2014-05-27 | Digital Processing Systems, LLC. | Electronic kiosk system and method for dispensing medical smart cards and managing healthcare information and services |
| US8848825B2 (en) * | 2011-09-22 | 2014-09-30 | Airbiquity Inc. | Echo cancellation in wireless inband signaling modem |
| CN105405446B (en) * | 2015-11-04 | 2018-11-20 | 中国电子科技集团公司第四十一研究所 | A kind of system and method inhibiting photographone echo noise |
| CN105847611B (en) * | 2016-03-21 | 2020-02-11 | 腾讯科技（深圳）有限公司 | Echo time delay detection method, echo cancellation chip and terminal equipment |
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- 2005-09-22 DE DE602005026542T patent/DE602005026542D1/en active Active
- 2005-09-22 WO PCT/US2005/034174 patent/WO2006041650A1/en active Application Filing
- 2005-09-22 EP EP05800746A patent/EP1797648B1/en not_active Not-in-force
- 2005-09-22 AT AT05800746T patent/ATE499754T1/en not_active IP Right Cessation
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Also Published As
| Publication number | Publication date |
|---|---|
| EP1797648A1 (en) | 2007-06-20 |
| EP1797648B1 (en) | 2011-02-23 |
| DE602005026542D1 (en) | 2011-04-07 |
| CN101019338A (en) | 2007-08-15 |
| WO2006041650A1 (en) | 2006-04-20 |
| US7583621B2 (en) | 2009-09-01 |
| ATE499754T1 (en) | 2011-03-15 |
| US20060072484A1 (en) | 2006-04-06 |
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